Show a "cursor" in the editor while popover is open

[helen]

Is your enhancement related to a problem? Please describe. When the popover is open, the text cursor jumps into the filter input. There's a little arrow pointing to the insertion point but it's not really visually super-precise to let you know where exactly you're inserting.

Describe the solution you'd like I would like to see a faux-cursor. I think it's a matter of inserting a temporary span and styling it up appropriately. It's actually probably best if it doesn't blink.

Designs None at the moment

Describe alternatives you've considered n/a

Additional context n/a